340 Shark and Co77ipa?iy 



The Lake Nicaragua shark (Carcharhinus nicaraguensis) . 



Courtesy, The Sears Foundation for Marine Research from 

 Fishes of the Western North Atlantic by Henry B. Bigelow and Wilham C. Schroeder, 1948 



have been caught far inland in the roadside canals that lace south central 

 Florida. 



Sharks are not the only oceanic dwellers in the 100-mile-long Lake 

 Nicaragua. Tarpon are found there, as are the shark's close relatives, 

 the Sawfish, and the inevitable companions of sharks, remoras. Lake 

 Nicaragua's sharks, known to scientists only since 1877, seem to be a par- 

 ticularly nasty breed. In the spring of 1944, a single shark attacked three 

 persons near Granada, the lake's principal town. Two of the victims died. 

 Natives say that at least one person a year is claimed by the sharks. Nu- 

 merous dogs have been devoured by the sharks, which are locally re- 

 nowned for their voracious appetites. They will readily seize meat or 

 fresh-fish bait. 



Between Lake Nicaragua and much smaller Lake Managua is an 

 erratically flowing river, the Tipitapa. Waters of Lake Managua, which 

 is about 15 feet higher than Lake Nicaragua, are believed to flow into 

 Lake Nicaragua underground. But about once every decade or so, 

 the normally dry riverbed of the Tipitapa is coursed by water from Lake 

 Managua. Thus, at these times, the water connection between the two 

 lakes is indisputable. Yet neither sharks, sawfish, nor tarpon have ever 

 been reported in Lake Managua. 



The two lakes, like much of the western portion of Nicaragua itself 

 and the entire Central American isthmus, lie on a restless part of the 

 earth's crust. A string of 23 volcanoes, many of them still active, runs 

 down the western side of Nicaragua. One of the active peaks, Concepcion, 

 rises from the island of Ometepe in Lake Nicaragua. Another volcano 

 in the long Une of peaks, Coseguina, literally blew its top in 1835, ex- 

 ploding with a roar heard in Bogota, 1,100 miles away, and spewing 



